Pyrethroids: A Safe Label Doesnt Make it Safe

The dangers of old-fashioned pesticides like arsenic, and more modern ones like chlorpyrifos (marketed as dursban and malathion), have led to a new generation of pesticides heralded as safe for mammals and birds.Photo: Greencolander, Creative Commons, Flickr

These third generation pesticides are known as permethrins and are derived from a chrysanthemum-type plant native to the Middle East (i.e., Dalmatia and the Caucasus). This woody perennial has flowers that, when dried and crushed, deliver a potent neurological poison to insects. Known as Persian Insect Powder, this all-natural remedy has been used for centuries to eradicate head lice, among other things.

One would assume that a pesticide (or insecticide) thats been around since the dawn of civilization would be environmentally-friendly, right? And one would be correct, if not for the fact that scientists took this natural bug remedy and reformulated it into a chemical compound that, with the addition of piperonyl butoxide, becomes a supertoxin to insects and a toxic, if less lethal, agent to every other living thing on the planet.

Piperonyl butoxide, a cytochrome P450 inhibitor, works by deactivating an insect’s (or a human’s) natural ability to defend itself against toxins. As a result, these synergized pyrethrins, or pyrethroids, actually double their toxicity in the bodies of bugs and remain there longer.

This one-two punch is not only more lethal to insects than the original pyrethrin, but measurably more deadly to fish. Its effect on humans is largely undocumented, but the current consensus is that piperonyl butoxide (a supposedly inert ingredient) may cause cancer, mutations and birth defects in humans. One thing is known. Common head lice shampoos using these pyrethroids can trigger allergic-type reactions that have led, in at least one documented case, to the death of a child.

Besides shampoos, pyrethroids can also be found in such products as flea collars for pets, indoor sprays for ants and roaches, carpet sprays aimed at controlling the spread of animal fleas, outdoor wear designed to repel mosquitoes and the like, and in supposedly environmentally-friendly lawn care products targeting insect infestations in grass, trees, shrubs and other ornamentals.

The trouble is, these designated “safe” pesticides are not safe, as witnessed in the 300-percent rise in reported incidents in a decade, from 261 in 1997 to 1,030 in 2007. According to the Center for Public Integrity (CPI), which took Environmental Protection Agency (EPA) data and translated it for human consumption, these pyrethroids now account for almost 26 percent of all human incidents reported, including moderate, serious and fatal occurrences.

While actual deaths (20 in a five-year span from 2003 to 2007) were minimal, the number of incidents  more than 6,000  is now greater than for any other class of insecticides, including the known toxic organophosphates and organochlorides, or even arsenic. This, even though EPA reporting includes only a fraction of the occurrences, since many were likely never reported because they were neither recognized nor diagnosed.

No one would have known the prevalence of pyrethroid poisonings if the CPI had not requested the information from the EPA under the Freedom of Information Act. The EPA grudgingly released the figures in 2008, and the results astonished even the scientific community.

The EPA is a government agency set up to protect the health and welfare of U.S. citizens, as is the U. S. Department of Agriculture, or USDA, which on May 21 of this year suspended its reporting of pesticides altogether.

This informational database, published annually by the USDA as the Agricultural Chemical Usage report, was instituted in 1990 to help farmers, fruit growers, agricultural inspectors, environmental agencies, and state and local representatives track pesticide use. The alternatives, costing hundreds of dollars, are unavailable to farmers, fruit growers and many environmental monitoring agencies, and the USDA’s lapse will increase the incidence of undiagnosed and unreported chemically-induced illnesses and fatalities.

Between the two agencies, both charged with protecting American citizens from chemical health hazards, this double-pronged assault on the publics right to know  either through obfuscations or outright failure  represents a potential hazard on an order of magnitude not seen since the beginning of the Industrial Revolution, when corporations first began subsuming the rights of the individual to the profit-driven motives of business. Labeling products, as is done on most lice shampoos, is no protection either, since many pediatricians and general practitioners dont know the dangers of pyrethroids, and allergies can develop instantaneously with no previous exposure.

You wont hear it from the EPA, but pyrethroids are not safe, especially for people with asthma, allergies and related conditions where the risk of anaphylactic shock is high. They also pose unknown risks for infants and children, whose neurological development may be hampered. In fact, a 1994 study of rats showed brain damage after two months of exposure to combined pyrethroids and allergy medication. They certainly are not safe for aquatic residents  fish, frogs and invertebrates  and they may not be as benign to bird populations as previously stated. This is particularly disturbing in light of the fact that migratory song birds eat bugs, and these birds are in serious decline everywhere around the world.

If you love your children, or pets (and if you also love nature), there are other, safer remedies for head lice. There are also a number of natural flea and tick repellants, and many of these will work in your home to discourage pests. Simply planting pyrethrums (also known as painted daisies, mums or asters) in your garden will deter outside bugs, and you can harvest the dried flower heads to make your own, all-natural insecticide.

We cant make the EPA, USDA and other, similar government agencies act more responsibly, but we can protect ourselves and the ones we love from their errors of omission (and their lapses from scientific credibility at the direction of the current administration).